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Wheel and Axle/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby. (flushing toilet) Moby is in a bathroom. Moby accidentally pulls off a doorknob. MOBY: Beep! (bang on the door) (2x) Tim is shown on the outside of the bathroom door. TIM: Are you stuck in the bathroom again? (bang on the door) Tim reads from a typed letter TIM: Dear Tim & Moby, can you tell me about the wheel? From, Valerie. The wheel is another device that falls under the category of "simple machine". But we can't really talk about wheels without also talking about axles. An animation shows two wheels. A rod stretches from the center of one of the wheels to the center of the other wheel. TIM: For a wheel to do any good, it has to rotate on a rod called an axle. An arrow travels around the rod. TIM: Like I said, the wheel and axle is a simple machine; like the lever, inclined plane, and pulley. Drawings show wheels and an axle, a lever, an incline plane, and a pulley. TIM: Simple machines are the most basic tools out there. They allow us to move things more easily by magnifying our efforts. The wheel and axle is actually a rotating lever that moves in a circular motion around a fulcrum. An animation shows two wheels connected by an axle. A line is drawn from the center of one of the wheels. The line rotates much like the hand of a clock. An arrow points from the line in the direction of movement, which is clockwise. MOBY: Beep? TIM: I think somebody needs to watch the levers movie. (bang on the door) (bang on the door) TIM: Okay, take this doorknob; it's a wheel and axle at work. An animation shows Tim pointing to a doorknob. TIM: The knob is our wheel, and this metal rod is the axle. Tim points to the doorknob and then points to the small rod that connects the doorknob to the door. TIM: And they turn around this point, which is called the fulcrum. Tim points to the center of the doorknob. TIM: Without a knob, it's pretty hard to turn the rod. Moby is trying to turn the small rod that connects the doorknob to the door. TIM: It takes a lot more effort. The big knob magnifies the force of the turning motion. Tim turns the doorknob. TIM: The wheel movement is turned into a shorter but more powerful force at the axle. (clicking) (bang on the door) TIM: You have to turn the outside of the wheel farther than you want the axle to turn, but that extra distance is translated into more turning power. It's a tradeoff. Moby uses a toothbrush to turn the small rod. (creaking door) Moby exits the bathroom. TIM: Hey, good job Moby! You've shown us that the wheel is just like a round lever! Is that my toothbrush? A toothbrush is attached to the small rod. Category:BrainPOP Transcripts Category:BrainPOP Engineering & Technology Transcripts